SNP MP Joanna Cherry has been asked to apologise after saying a rap song in which Scottish Conservative leader Ruth Davidson was branded "dykey" was "hilarious".

Scottish Conservatives equalities spokeswoman Annie Wells has written to the Edinburgh South West MP calling on her to "reassess her promotion" of the group and to apologise to Davidson.

Wells has also called on Cherry to join the organised by LGBT charity Stonewall No Bystanders campaign against homophobia.

The song was performed at a pro-independence event on Sunday which Cherry attended alongside former SNP leader Alex Salmond, Scottish Government minister Jeane Freeman and Green MSP Ross Greer.

Comedy group Witsherface sang: "Here's my girl, Mhairi 'Black Belt' B/With Nicola Sturgeon, minister primary/Versus Ruth 'Dykey' D/And Kezia Dugdale."

Cherry lauded the group's performance as "hilariously irreverent satire" and tweeted that she was "still laughing" afterwards.

When Twitter users challenged her description of the act, Cherry accused her opponents of "mansplaining" in a series of tweets across a six-hour period.

A spokesman for the Scottish Conservatives said: "The nationalists are always the first to scream offence at anything that even mildly upsets them. But when it's a joke at the expense of pro-UK campaigners, it's suddenly harmless and hilarious.

"The SNP should be lambasting this but instead its elected representatives are praising it on social media."

In response to Wells, Cherry said in a letter: "I saw yesterday's performance as a lesbian woman watching a satirical comedy sketch written by lesbian women and performed by lesbian women, which mocked representatives of all political parties, including the SNP.

"In that context I did not believe it was intended to be offensive but I do understand why some find it to be.

"Similarly, I do not believe Ruth Davidson MSP's recent comments about the openly gay politician Angela Eagle MP being a "short-haired, flat shoes, shovel-faced lesbian" were meant to be offensive but some may have taken it that way."

Cherry says she and other lesbians have "reclaimed" the word dyke and use it "proudly" but she regrets any offense caused over its useage at the pro-independence event.